About two-thirds of the lithium that should be in the early universe is missing. Perimeter researcher Maxim Pospelov thinks a hypothetical new particle – particle X – may have kept it from being formed.

Theorists from Perimeter and experimentalists from the Institute for Quantum Computing have found a new way to test whether the universe is quantum, a test that will have widespread applicability: they’ve proven the failure of noncontextuality in the lab.

Theoretical physics is more than a field of study. It’s a tool of discovery. Check out the latest issue of Inside the Perimeter to explore what is happening – and what is possible – in this fascinating realm.